DS03
by The14thMelody
Summary: When Sebastian unexpectedly contracts a demon illness with inhuman complications, its up to Ciel to try and take care of his butler. Slash, M for later chapters.
1. Chapter 1

**Disclaimer: I don't own Kuroshitsuji or any of the characters.**

It started on a day like any other. Sebastian was busy cleaning the library, dusting each book carefully. The butler was on the last shelf when he felt that tickle in his nose. Pausing, he waited for it to disappear before continuing his work. A couple minutes later however, it came back, and before he could try to stop it he found himself quietly sneezing against his arm.

A bit taken aback, Sebastian paused once more, now in thought. He never broke his image of the perfect butler, that means he never yawned, snorted, hiccuped, burped, coughed, and he most certainly didn't sneeze. He decided to drop it, and blamed his unseen action on the dust of the old books.

A little while later, while Sebastian was preparing dinner alone in the kitchen, he felt an itch in the back of his throat. He quickly cleared it, focusing on his work once more. It came back a few seconds later, and knowing what was coming, the butler covered his mouth and turned away from the precious food, keeping it sanitary. The cough was small and almost inaudible, but very uncharacteristic of the butler once again. He knew he couldn't just ignore the misshapes that had happened, even if they were small. Demons do not just cough or sneeze. Oh yes, this could be the beginning of something terrible.

Sebastian only hoped for the best as he put the issue in the back of his mind.

Early the next morning, long before anyone else was up, Sebastian felt the first big sign of his sickness. During the night, the demon rarely slept. Instead he focused on odd jobs to keep him occupied. This was one of the few time he could relax, and take his jacket off.

As Sebastian was refilling the water in the icebox, he was faced with a sudden but harsh coughing fit, one of which he couldn't hold back. It didn't last long, but his throat burned when it was done, and his breathing had gotten heavy. The butler felt drowsy, and when he straightened himself his head swam. It was certain now.

The demon had contracted an illness.

Sebastian headed to his room to think about what to do. He wasn't sure what he had or where he had gotten it, but he knew it could interfere with his work. If what had happened in the icebox happened in the company of another, especially his young master, he would disgrace his butler name and fail his job. He couldn't let that happen.

Luckily, humans couldn't get a demons sickness. Its a good thing too, because a demon's illness is many times worst than a human's and would undoubtedly kill something so frail. However, a demon's sickness is much longer, and Sebastian had yet to learn what exactly it was he had. Hopefully it was just a cold, but it was to early to say.

Worst case scenario, he had DS03. A sickness that started as any common cold, but lasted much longer, and had the worst kind of side effects.

Hopefully that was not the case.

Sebastian checked his precious pocket watch that his young master has given him. It was almost time to wake the other servants. The butler inhaled, and realized he was a bit congested. He quickly blew his nose and held down a cough before starting his undoubtedly long day.


	2. Chapter 2

"Sebastian."

"Yes Young Master?" Tickle.

"All this paperwork is suffocating me. Bring something sweet."

"Young Master, we talked about this. You must stick to eating the correct meals in order to stay healthy." Tickle. Tickle.

"Just do it. Don't hassle me."

"Yes Young Master." Tickle. Tickle. Tickle.

Sebastian could barely contain the cough that was forcing it's way up his throat. As soon as the door shut behind him, he coughed into his sleeve as quietly as he could, sighing with relief as the tickle that had been driving him crazy subsided for the moment. That was the third close call that morning. The poor butler was getting more and more frustrated as the day progressed.

Sebastian checked his watch, it wasn't even noon yet. He knew if his case was just a cold that it could last for up to two weeks with no harsher symptoms than he was already experiencing, but he was going insane with just them alone. If this was worst than a cold, he would truly be facing his match.

Around the time when he was preparing breakfast about two hours before, he had started to encounter dizzy spells. His vision would blur for just a few seconds before it righted itself again, nothing he couldn't handle, but annoying non the less. That was also the last symptom of the cold. If he got another one, he would have to figure out a plan that might involve drastic measures.

As Sebastian prepared a small cheese cake for his Young Master, he thought about his escape route if he did indeed have DS03. The medicine to cure the sickness was not something easily acquired. He knew that if it came down to it, he would be sick for up to two to three months, and would have to turn to the reapers, as they shared sicknesses with demons. Sebastian was sure he could ask The Undertaker if he had to, but even then it wasn't a sure deal. Also, dealing with the symptoms of DS03 was a messy job, one of which he wasn't sure he could handle on his own in his condition. Sinking to the point of asking a reaper for medicine was one thing, but he most certainly wouldn't stoop to letting one care for him. His pride simply wouldn't allow it. No human who didn't know of his real nature would be able to, as they would indubitably be suspicious by the symptoms of the illness, as they weren't all human. That left his Young Master as the only one able to take care of him, which he also refused to let happen. It wasn't just because of his duty to be the perfect butler, or to hold a strong front before the young earl. It wasn't even about his pride, because in his book, having a human care for him was better than a reaper. No, the only reason that came to his mind was because he simply didn't want Ciel to see such a hideous side of himself, not that he knew his reasoning for that either.

But alas, all the butler could do for now was hope for the best outcome. It was only a matter of time before he found out anyway.

Sebastian's thoughts were interrupted by the bell to the study ringing behind him. His Young master was getting impatient. He took the sweet he made upstairs, and knocked on the door twice before letting himself inside. Ciel was already glaring in his direction when he stepped through the door.

"You took to long." Ciel said, narrowing his gaze.

"My apologies." Sebastian smirked slightly at the sheer bossiness of his master. He had always found it amusing. In a second he was setting the plate down in front of Ciel, who eyed it for a second before looking slightly satisfied. "I've prepared Strawberry cheesecake with hand made cream. I hope it's to the lord's liking."

Ciel took a bite and said nothing, but he kept eating the pastry, a sure sign that he approved. Sebastian was nonchalantly watching him eat, pleased to be done with the task, and thinking up a lighter dinner than the one planned. Ciel wouldn't be able to finish one of usual size now that he ate at two o'clock. Speaking of which, it was almost tea time.

"Then, If the master doesn't need me, I shall prepare the tea." Sebastian said, already turning around to exit the room.

"Wait." The butler stopped suddenly at the command, and all of a sudden the room started to spin. He knew it was just a dizzy spell from moving to quickly, and cursed himself for being so careless. A couple seconds later, it hadn't ceased, and Sebastian started to become alarmed. He could hear Ciel call his name in confusion as to why he hadn't turned around but his heartbeat was loud in his ears and he couldn't find the voice to respond. His body unwillingly backed up a bit before he hit the desk behind him where he leaned against it.

Finally, Sebastian's head cleared and when he came to completely, he was met with a confused, slightly alarmed Ciel and a headache. One hand was gripping the desk and the other was gripping his head. He could tell his face showed alarm, and he was panting slightly. Sebastian immediately but carefully straightened up and continued as if nothing had happened.

"Yes Young Master?"

"What the hell was that?" Ciel practically yelled. Sebastian mentally winced and the throbbing in his head.

"What was what?"

"You, you...swayed a bit...Sebastian. Come here." Sebastian silently did as he was told, going around the desk and standing next to Ciel's chair. The young boy turned, reached up and placed a cool hand on his forehead. Sebastian unwillingly sighed a bit at the touch, it was cold on his surprisingly hot skin.

"Sebastian, your burning. Are...are you sick?" The butler couldn't lie.

"Im...afraid so..."

"...Sebastian. You let this get in the way of your job. Theres no choice. Go rest. I'll check on you later to give you further instructions and you are going to tell me exactly whats going on." Ciel looked angry but Sebastian noticed it wasn't hostile like many of the other times he got angry, but kinda scoldingly, like a mother to her child. The butler couldn't help but smirk. Oh, how his Young Master was full of surprises.

"Yes, My lo-lor-lorchoo~!" Sebastian quickly wiped his nose, surprised by the random sneeze he had not felt coming. "Please Excuse me." He stated immediately after. To his surprise, Ciel merely laughed; a small chuckle.

"Get going Sebastian, before I make you work as you are." The young earl said smirking a bit. He was already having fun with this, seeing just the bit of humanity his Butler was showing made Ciel feel unnaturally happy. He almost felt superior to the nearly unbreakable demon and he just couldn't hide his mirth.

Sebastian grimaced, aware what Ciel was so pleased about. He quickly exited the room, making his way to the servant's quarters.

Sebastian barely used his room. Though it was rather spacious and adorned with everything a normal human needed, a demon such as himself didn't need such things. At night, the butler was usually busy, and the rare times he had some free time, he usually found something that piped his interest for a while before he was busy yet again. A demon didn't need sleep, it was something he could do for the luxury, but thats it, and he's never quite enjoyed dozing off as he was never got tired like a human did. The only real thing he used his room for was housing the occasional stray cat he found wandering the grounds, though they never stayed long.

However, when Sebastian stepped into his warm abode, he found himself drawn to the bed. Opening the window to try to cool the room a bit, the butler began removing his coat and shoes and sitting on the mattress. It sunk under his weight, and before he knew it, he was laying atop it, not bothering to cover his body. His mind drifted, and he felt his eye lids grow heavy, a feeling he hadn't experienced in a long time; he was actually tired. The demon weakly tried to fight the growing need to sleep in vain, and before he finally yielded to it, he vaguely wondered if his Young Master would actually come check on him.


	3. Chapter 3

Ciel would never admit he was amazed. He had never seen his butler act so venerable before. It both fascinated him and, dare he say it, worried him as well. During the next few hours after the incident with Sebastian, he wondered about whether actually checking on his butler or not. As the head of the Phantomhive household, it was his responsibility to keep his servants in working condition and he had told Sebastian he would check up on him. It was only natural for a man to keep his word, and the young earl would not hurt his pride by breaking it. But on the other hand, Sebastian wasn't just any old servant; he could take care of himself couldn't he? Showing any sign of _care _to the demon would hurt his pride just as much. Ciel could simply ask another one of his servants to check on his butler, but he wasn't a fool. He knew Sebastian was indeed a demon, and even if this was a simple cold, the earl didn't know any details, thus he wouldn't compromise that secret. Finally Ciel decided to just check on his butler and get it over with.

Ciel knew his mansion like the back of his hand, even the places he never went. Finding Sebastian's room was easy as if there was a clear SM engraved on the door handle. Ciel knocked and impatiently waited for a reply. None came however, and Ciel tried again, to no avail. Slightly annoyed, the young earl chose to just open the door slowly, giving the demon plenty of time to stop him if needed.

It was freezing inside the room. The window was open and moonlight poured in, bathing the room in a silvery light. Ciel pulled his coat closer and took a step inside. He hesitantly closed the window in an attempt to warm the room a bit and turned his attention to the bed, where a rather large lump lay. The young earl approached it slowly almost in disbelief as to what he saw.

Sebastian had mentioned to him before that he didn't need sleep, and yet there was his butler, sprawled atop the blankets in a quiet slumber. His hair was spread across his face and his breath came out slightly uneven. Ciel felt himself blush slightly, and almost turned and walked out of the room right then and there, but common sense forced him to stay. Hesitantly, the earl brushed aside the hair on Sebastian's face, and placed his hand upon the demon's forehead. It burned to the touch but the butler leaned slightly into the foreign appendage. Ciel whisked his hand away quickly, surprised and slightly panicked that Sebastian actually had a fever.

Ciel knew he couldn't leave his butler like this; he had to do something to bring his fever down. Without even thinking it through, he found himself with a bowl of ice water and a rag. Ciel removed his ring to keep it safe (keeping his father's keepsake on but removing the one with the Phantomhive crest), then dipped the rag thoroughly, rung it out and placed it on Sebastian's head, making sure it stayed in place. The earl left the room in a rush, glad to be out.

Ciel was appalled that he actually did it. He convinced himself Sebastian was asleep and would not know anything. When his butler asked, he would blame it on Maylene. There was nothing to worry about, but Ciel had to keep forcing his mind to think about something other than his ill butler as he got back to work.

It was a couple hours later when the butler woke up. Moonlight poured through the window, and the first thing that came to his drowsy mind was the time. He sat up quickly, swooning a bit, to check his pocket watch in his jacket pocket. Before he got up however, Sebastian noticed a now dry rag fall from his face and onto his lap. He gaped at it and looked for the thing he needed to actually confirm his suspicion, the water bowl. It sat on his bedside table, shining in all it's glory.

The butler had been cared for. It was a shock that Sebastian actually slept, and to his horror he discovered it was the early hours of the morning. His Young Master was undoubtably in bed. But to find himself actually being in the care of a human was more shocking than he had anticipated. Then, which human? His Young Master perhaps?

The demon found himself wishing that to be the case.

Looking for more evidence, Sebastian also noticed the closed window, and the small golden ring sitting next to the bowl of lukewarm water with the Phantomhive's crest upon it: Ciel's less valuable accessory that named him the public head of the family. The butler's mind connected the dots instantly, and he smiled a bit before examined the ring closer. It was cold against his heated fingers, and held his master's lingering scent. A comforting feeling overtook him and he leaned against the wall in an uncharacteristic position of comfort.

Feeling oddly content, the butler focused on his situation. He had a fever; his symptoms were getting worst, the dizzy spells were getting longer. And he even showed weakness to his Young Master, not to mention he slept in front of him too, something that Sebastian never dreamed would happen. The situation was indeed grim.

The demon was very logical, he never ran away from the truth of the matter. And this was something he had to act immediately upon. He didn't want to admit it, but he was almost certain.

He had contracted DS03.


	4. Chapter 4

When Sebastian finally got out of bed and dressed properly again, he realized it was already time to wake the other servants. Unfortunately, his head throbbed as soon as he rose himself from the mattress.

The butler wasn't completely unprepared, he kept two simple demon made medicines for situations such as the one he found himself in. He had two. One was a numbing pill; Used to numb discomfort, mentally or physically. It was usually used for large wounds, or on some occasions, tormented demons who wanted release from their _mental issues._

The reason it was used for such drastic instances was because it was pretty extreme; clouding your senses and judgment before putting yourself in a pleasurable high. One should be supervised, as an individual taking the pill would most certainly not feel any pain, but could get themselves into dangerous situations from lack of judgment. It was dangerous to take too many, as they have been known to temporarily alter a demon's consciousness.

Pretty much, the pill was a last resort.

The second medication Sebastian had was a simple but effective prolonging pill. All it did was temporarily prolong upcoming symptoms but also gather all the ones missed. The longer prolonged the symptoms, the worst they would be when finally suffering them. This pill wasn't usually used because most demons like to just get the effects out of the way and recover rather than prolonging the illness. But for demons who were in a contract, it unfortunately came in handy for serving their master.

Sebastian didn't want to take this pill unless absolutely necessary. He knew he was already going to have terrible symptoms; he didn't want to make them worse by prolonging them when they were inevitable anyway. He would only take this pill if he had to do a large or dangerous job for his Young Master.

Sadly, neither pill would help cure his illness, only alter it.

After Sebastian woke the other servants, he headed to Ciel's room to wake him up. The butler stood outside the plain door, observing his shadow cast upon it. Taking a deep breath, and ignoring his still throbbing head, he opened the door and officially began the day.

Sebastian was the only one who saw the weaker, more vulnerable side of Ciel. And as always, when the butler opened that door, he was greeted with the sleeping face of his master and a dimmed bedroom.

Ciel didn't know that every morning, Sebastian observed him sleeping. Not for long, no, but the butler had always found it amusing how the earl would make it so obvious he was in a dream, or sometimes, even let a bit of saliva drip from his mouth. Sebastian enjoyed seeing this laid back side of Ciel that no one else saw. It was his right after all, as Ciel's butler and demon.

This morning was no different. Sebastian approached the king sized bed and gazed down at his Young Master. The butler couldn't help but think back to the night before, when Ciel had taken care of him. How he wished he could have been awake for such a once in a lifetime event.

"_All well," _he thought, "_There are bound to be more entertaining sights to come."_

A smirk graced the butlers lips. He felt like the expression was off for the situation, but it had been so very long since he had actually smiled; This was the closest he ever got.

Ciel's face scrunched up a bit.

_"Ah, he's dreaming." _Sebastian thought, brushing some metallic hair from the young boy's face. Judging from said boy's face however, it was a nightmare.

Ciel shifted a bit, grimacing every couple of seconds. He was having _that_ dream again.

For as long as Sebastian had served Ciel, the boy has always had a certain nightmare. Ciel obviously never mentioned it, and was determined not to show such a weakness as fear in front of his butler. Yes, Ciel was most terrified of that dream, it was probably the only thing in this world that the young earl was actually afraid of, as far as Sebastian knew.

Ciel thought his butler was in the dark about the dream, but not only did Sebastian know of his fear, he also knew what Ciel's dream was about. It was a perfect recollection of his past. The painful memories that had shaped such a perfectly sinned child, and brought Sebastian to said child. When Ciel had this nightmare, Sebastian always woke him up if he was there. Truthfully speaking, he knew when his Young Master had the dream at all times. He could feel the waves of panic from the young boy even if he was miles away.

Yet he mostly did nothing of it, because he knew Ciel had his pride; the thing he cared for most. That was why he couldn't let his master know that he knew.

Still, when Sebastian was in Ciel's presence during such a dream, he had the power to play the clueless. To say, "It's time to wake up Young Master," like he always did and let Ciel think he didn't know of his struggling. That was why, in this situation, Sebastian rushed to the curtains and yanked them apart a little too ungracefully for a butler of his stature. Then putting on his perfect, unbreakable poker face, He woke his Master up, like he did every morning and the butler never let his face slip, even when his body flooded with relief when Ciel opened his eyes and put on that stoic annoyed face like he always did.

Tea was served and a newspaper was given. Ciel seemed to act like the night before hadn't happened. Still though, every once in a while, Ciel would glance up at the butler, with an analyzing look, like he was trying to find a symptom of sickness on that devilish face.

Sebastian, on the other hand, was doing better at the moment. Other than the throbbing headache and the slight fatigue, he felt fine. The butler merely watched as Ciel downed the rest of his tea and placed the saucer on his bedside table.

"So," he started. "Explain." Sebastian didn't need to ask about the topic. He immediately began his explanation.

"Well, Young Master, it would seem that I have contracted a illness called DS03. It is a semi-common sickness to demons, angels and shinigami. It's similar to the common flu humans get, but because demons live much longer lives and are much more able, the sickness isn't contracted near as often and lasts much longer."

"How long?"

"It is hard to tell you exactly, but my estimate is two months at best." Sebastian mentally prepared himself so he wouldn't cringe.

"TWO MONTHS!?" Sebastian cringed both physically and mentally despite his preparation. He felt a painful throb in his head. Ciel noticed and slightly regretted his outburst. "Two months isn't acceptable," he continued.

"I apologize for the inconvenience, but you needn't worry. I shall carry out my duties per usual. I will not disgrace the Phantomhive name as a butler of the family." Sebastian got on his knee and placed his hand over his heart. Ciel gazed at him with the same expression as usual.

"Get up Sebastian." The butler obliged. Ciel locked eyes with the demon. "I expect you not to disappoint me. You are my butler, and as such you should never fail me. Just..." The earl turned his gaze away to the floor, and Sebastian couldn't believe the hint of red on his master's cheek. "...Just don't overdo it, Alright?"

Sebastian said nothing for a moment, captivated with the young boy's face, then he smirked. The feeling that the expression wasn't the one that should be on his face was felt once again, but he could not be bothered to think about it before he was ushered out the door by a hungry and still undressed boy.

The day went on per usual, but Sebastian continued to feel sick. His headache hadn't gone away, and he coughed more often than he would have liked. The butler had already come to terms with his fate for the next couple months, and he decided to do everything he could to seem like the sickness wasn't there.

Sebastian had never gotten sick before, he had only read and heard stories from those who had. He knew some of the symptoms, most of which he had already experienced. But there was still one he knew he was to get, but hadn't yet.

Nausea. And even then, it wouldn't finish.

Sebastian was certain the symptom was going to appear soon, so all day he prepared himself. He expected it often, and would make sure not to get in any situation he couldn't escape from in a moment's notice. He hung to the side of everything.

Finally, later that night, when Sebastian was tracking down a stray cat he had seen earlier that day, it hit him. Sebastian was leaning over a rose bush when a blinding stab of pain erupted in his stomach. He instantly knew what was going on but before he could actually prepare himself, a glob of _something_ came out of his mouth and landed on a rose underneath him.

Something boiling, smooth and... _black_. It burned his throat as he spit it out, and as soon as he saw it, he could feel more forcing its way up. Sebastian doubled over onto his knees and buried his head into the bush as scorching bile landed on the soil beneath him. It tasted bitter, and a bit like blood. Its smooth black texture allowed it to shine in the moonlight.

By the time he was finished, Sebastian was panting and swallowing furiously. He couldn't lift his head, or even move from the sheer amount of energy the incident had drained from him. His eyes were clouded and he couldn't see straight. The butler hadn't expected it to be _that_ bad. All he could hear was his heart pounding in his cranium. He rested his head on an arm that was supporting him until the pounding in his head calmed a bit, and his stomach pains resided completely.

The butler leaned back, settling on the dirt in a uncharacteristic relaxed posture to further observe the situation. The rose bush he has leaned in to was dead and brown. Every part of it was dried; the cracked buds that had once been roses hung limp on their shriveled stems. Movement caught Sebastian's intention and he watched as a leaf broke from the now dead plant and _dissolved_ in the black substance underneath, sizzling as it disappeared. The substance then sunk into the dirt leaving a black patch where it once sat.

The butler made a mental note not to let whatever it was he had coughed up touch anything important.


	5. Chapter 5

Sebastian decided to contact the Undertaker. He knew that is he had any chance at getting a medicine for his illness that the silver haired reaper would be it. The butler's movements had been slowed ever since his mishap in the garden that night. He could tell Ciel had begun to notice a decrease in his efficiency and Sebastian couldn't stand to let it get any worse.

The meeting with the Undertaker was set for that night at midnight in the reaper's shop. As Sebastian went throughout the day, he felt Ciel's eyes on him as he had gotten used too. He knew Ciel was studying him, trying to find the tiniest bit of a sign of sickness from the butler, and it took a great deal of energy to hide all his symptoms from the boy's eyes. He just wanted to get the medicine quickly and without alarming the boy.

Later that evening, when Sebastian was tucking Ciel in for the night. Sebastian noticed Ciel blatantly staring at him, not even trying to hide his interest. The butler actually felt sorry for the boy in the fact that he had to resort to this in order to get more information from his butler.

"Yes, Young master?" Sebastian sighed.

"What?" Ciel retorted, not taking his eyes off the man.

"You have something you want to say, do you not?"

Ciel was quiet for a second, his expression unchanging. "Are you okay?" He said simply. The question took Sebastian by surprise. The demon had been expecting something more gruff and demanding. An order maybe, but the question asked was most certainly nothing of the sort. It was extremely uncharacteristic of the boy.

Sebastian's face must have shown something, for after a second Ciel quickly turned away from the light of the candelabra and murmured a quick "Never mind" as he rolled over, his face out of view from the butler.

Sebastian didn't say anything for a moment before putting his hand on the boys temple as a gesture of understanding. He couldn't stop himself as he responded to Ciel's question.

"I'm fine." He said keeping his hand where it was for a few more moments. The boy didn't respond so Sebastian blew out the candles and left the room. Too tired to think about what had come over him, he retreated to his chambers.

Ciel was not convinced. He had been watching Sebastian for a couple days now, trying to analyze how bad his butler's condition was. Ciel, knowing Sebastian enough, noticed a couple things.

Sebastian was slower, not by much, but enough for Ciel to notice. He was also much less talkative, only speaking when needing to. He kept his head down much more often, rarely even looking Ciel in the eyes. And now, as he laid in his bed staring at the ceiling. He recalled how hot Sebastian's hand was, even through the glove as he touched his face. The memory made Ciel blush and hide his face stubbornly in the blankets.

Making up his mind after a moment to thinking, Ciel jumped up from bed and grabbed his eyepatch and a cloak that covered his nightgown, and followed after Sebastian.

He ran through the house, stopping at the kitchen and dining room on his way to Sebastian's room. He wasn't sure what Sebastian did after Ciel went to bed, but since that was the only place he had seen his butler this late at night, he followed his instinct and proceeded to the servant's quarters. When he got there, he didn't knock and instead threw the door open. He was greeted with the sight of a startled Sebastian kneeling on the window sill. There was moment of startled silence.

"Sebastian?" Ciel questioned without taking his eyes off the demon's. "Where are you going?"


End file.
